Fixed #31777 -- Added support for database collations to Char/TextFields.

Thanks Simon Charette and Mariusz Felisiak for reviews.

1 files changed, 19 insertions, 10 deletions

diff --git a/django/db/backends/oracle/introspection.py b/django/db/backends/oracle/introspection.py
index 41ffb68afb..a5df7f1297 100644
--- a/django/db/backends/oracle/introspection.py
+++ b/django/db/backends/oracle/introspection.py
@@ -95,14 +95,20 @@ class DatabaseIntrospection(BaseDatabaseIntrospection):
         # user_tab_columns gives data default for columns
         cursor.execute("""
             SELECT
-                column_name,
-                data_default,
+                user_tab_cols.column_name,
+                user_tab_cols.data_default,
                 CASE
-                    WHEN char_used IS NULL THEN data_length
-                    ELSE char_length
+                    WHEN user_tab_cols.collation = user_tables.default_collation
+                    THEN NULL
+                    ELSE user_tab_cols.collation
+                END collation,
+                CASE
+                    WHEN user_tab_cols.char_used IS NULL
+                    THEN user_tab_cols.data_length
+                    ELSE user_tab_cols.char_length
                 END as internal_size,
                 CASE
-                    WHEN identity_column = 'YES' THEN 1
+                    WHEN user_tab_cols.identity_column = 'YES' THEN 1
                     ELSE 0
                 END as is_autofield,
                 CASE
@@ -117,10 +123,13 @@ class DatabaseIntrospection(BaseDatabaseIntrospection):
                     ELSE 0
                 END as is_json
             FROM user_tab_cols
-            WHERE table_name = UPPER(%s)""", [table_name])
+            LEFT OUTER JOIN
+                user_tables ON user_tables.table_name = user_tab_cols.table_name
+            WHERE user_tab_cols.table_name = UPPER(%s)
+        """, [table_name])
         field_map = {
-            column: (internal_size, default if default != 'NULL' else None, is_autofield, is_json)
-            for column, default, internal_size, is_autofield, is_json in cursor.fetchall()
+            column: (internal_size, default if default != 'NULL' else None, collation, is_autofield, is_json)
+            for column, default, collation, internal_size, is_autofield, is_json in cursor.fetchall()
         }
         self.cache_bust_counter += 1
         cursor.execute("SELECT * FROM {} WHERE ROWNUM < 2 AND {} > 0".format(
@@ -129,11 +138,11 @@ class DatabaseIntrospection(BaseDatabaseIntrospection):
         description = []
         for desc in cursor.description:
             name = desc[0]
-            internal_size, default, is_autofield, is_json = field_map[name]
+            internal_size, default, collation, is_autofield, is_json = field_map[name]
             name = name % {}  # cx_Oracle, for some reason, doubles percent signs.
             description.append(FieldInfo(
                 self.identifier_converter(name), *desc[1:3], internal_size, desc[4] or 0,
-                desc[5] or 0, *desc[6:], default, is_autofield, is_json,
+                desc[5] or 0, *desc[6:], default, collation, is_autofield, is_json,
             ))
         return description